Objective.The purpose of this study was to determine the impact of intraoperative ultrasound（IOUS）on the management of patients with neoplasms of the liver. Methods.Forty nine patients operated on for liver or other pathologic processes were examined intraoperatively with 5.0 MHz special ultrasound transducers during surgical exploration of the abdomen.Subjects were evaluated because of known or suspected disease of the liver.Preoperative imaging studies included percutaneous ultrasound（n=49）

magnetic resonance imaging（n=11）

and computed tomography（n=34）.Intraoperative evaluation on all patients included inspection

bimanual palpation

and ultrasonography.Comparison between preoperative imagings and IOUS were analysed. Results.Sensitivity for detection of hepatic neoplasms showed in intraoperative ultrasound

percutaneous ultrasound

magnetic resonance imaging and computed tomography as 100%（23/23）

74%（17/23）

74%（14/19） and 75%（6/8）.Specificity showed 100%（26/26）

100%（26/26）

93%（14/15） and 67（2/3）.In seven patients（14%）

the neoplasms were not found by inspection

bimanual palpation

and identified only by IOUS. Conclusions.Intraoperative ultrasound is the most sensitive and specific method for detection and surgery of liver neoplasms

especially the occult neoplasms and small size lesion（<2cm）.